Do We Need All These Species?

Is there reason to be concerned about the loss of life’s diversity? Do we really need such a variety of species? Many respected experts insist that the answer is yes. Earth’s endowment of species provides humans with food, useful chemicals, and many other products and services. Think, too, about the potential benefits that undiscovered species may hold for mankind. For example, it has been estimated that 120 of the top 150 prescription drugs used in the United States come from natural compounds. Thus, in losing the flora of the world, mankind also loses the opportunity to find new drugs and chemicals. “Every time we lose a species, we lose an option for the future,” says Sir Ghillean Prance, director of Kew Gardens in London. “We lose a potential cure for AIDS or a virus-resistant crop. So we must somehow stop losing species, not just for the sake of our planet but for our own . . . needs and uses.”

We also need natural ecosystems to provide essential services on which all living things depend. The production of oxygen, the purification of water, the filtering of pollutants, and the prevention of soil erosion are all vital functions performed by healthy ecosystems.

Insects provide pollination services. Frogs, fish, and birds control pests; mussels and other aquatic organisms cleanse our water supplies; plants and microorganisms create our soils. The economic value of all these services is immense. A conservative estimate of the monetary benefits of biodiversity worldwide is around 3,000 billion dollars per year, at 1995 prices.

Scientist Anthony C. Janetos, writing in Consequences magazine, stated: “Many would agree that as a society we bear the ethical obligation to protect the habitability of the planet, and to act as responsible stewards of its biological riches for the present and future welfare of the human species. To do that requires an appreciation of the value of biodiversity—both what it provides for the natural world and the ways we can use it—and a commitment to preserve it.”